Authentication using graphene based devices as physical unclonable functions

Abstract

The present disclosure relates to secure devices having a physical unclonable function and methods of manufacturing such secure devices. One device includes at least one graphene layer representing a physical unclonable function and a measurement circuit for measuring at least one property of the at least one graphene layer. Another device includes at least a first graphene layer and a second graphene layer representing a physical unclonable function, where one of the graphene layers has been subjected to a variability enhancement such that a measurable property is different for each of the layers. A method includes providing a substrate for a secure device and providing at least one graphene layer on the substrate, the at least one graphene layer representing a physical unclonable function. The providing of the at least one graphene layer includes applying at least one variability enhancement to the at least one graphene layer.

What is claimed is: 
     
       1. A secure device having a physical unclonable function, the secure device comprising:
 at least one graphene layer, wherein the at least one graphene layer comprises the physical unclonable function; and 
 a measurement circuit, wherein the measurement circuit is configured to measure at least one property of the at least one graphene layer for authenticating the secure device. 
 
     
     
       2. The secure device of  claim 1 , further comprising:
 a seed layer. 
 
     
     
       3. The secure device of  claim 2 , wherein the seed layer comprises aluminum oxynitride or nitrogen dioxide. 
     
     
       4. The secure device of  claim 2 , wherein the seed layer is formed by atomic layer deposition. 
     
     
       5. The secure device of  claim 2 , wherein the seed layer comprises:
 titanium oxide or aluminum oxide for adhesion of a passivation layer. 
 
     
     
       6. The secure device of  claim 5 , wherein the titanium oxide or aluminum oxide comprises thermally evaporated or electron beam evaporated titanium or aluminum. 
     
     
       7. The secure device of  claim 1 , further comprising:
 a passivation layer. 
 
     
     
       8. The secure device of  claim 7 , wherein the passivation layer is formed by atomic layer deposition. 
     
     
       9. The secure device of  claim 7 , wherein the passivation layer comprises silicon nitride. 
     
     
       10. The secure device of  claim 7 , wherein the passivation layer is formed by chemical vapor deposition. 
     
     
       11. The secure device of  claim 7 , wherein the passivation layer comprises a multilayer, the multilayer comprising at least one layer of a polyacrylate film and at least one layer of an inorganic oxide. 
     
     
       12. The secure device of  claim 7 , wherein the passivation layer comprises a poly-para-xylene polymer. 
     
     
       13. The secure device of  claim 7 , wherein the passivation layer comprises a high-k dielectric. 
     
     
       14. The secure device of  claim 13 , wherein the high-k dielectric comprises at least one of:
 hafnium oxide; 
 aluminum oxide; 
 tantalum oxide; or 
 titanium dioxide. 
 
     
     
       15. The secure device of  claim 1 , further comprising:
 a buffer layer comprising a low-k polymer. 
 
     
     
       16. The secure device of  claim 1 , wherein the at least one layer of graphene has been subjected to a variability enhancement comprising at least one of:
 an exposure to ozone; or 
 an exposure to perylene tetracarboxylic acid. 
 
     
     
       17. The secure device of  claim 1 , further comprising:
 a source electrode; and 
 a drain electrode, wherein the at least one graphene layer is located between the source electrode and the drain electrode. 
 
     
     
       18. The secure device of  claim 1 , wherein the measurement circuit is configured to derive a signature having one or more physical unclonable function values from the at least one property. 
     
     
       19. The secure device of  claim 18 , wherein the measurement circuit is further configured to derive a binary key from the signature, wherein the binary key is derived from the signature via the measurement circuit by applying a threshold to the one or more physical unclonable function values. 
     
     
       20. The secure device of  claim 1 , wherein the at least one property of the at least one layer of graphene that is measured by the measurement circuit comprises at least one of:
 a resistance; 
 a capacitance; 
 an impedance; 
 an inductance; 
 a transmittance; or 
 a voltage response.